This may sound racist and classist and I'll just take the heat, but I suspect that for the most part rates are steady for different demographic and economic groups across state lines. Some states are just blessed with more diverse populations that others. ETA: looking at more data, I've got to say, I'm probably wrong. I can't really tell though because for some states, I think the economic situation may explain a lot and I don't have data for that. The south must just be that much more fertile.
ETA:
http://www.guttmacher.org/pubs/2006/09/12/USTPstats.pdf
It's from 2006.
This has more info, even of the type that DSTren notes.
"Fifty percent or more of teenage pregnancies end in abortion in New Jersey, New York, Massachusetts and the District of Columbia."